If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". What is A2 If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". A2.a3.a4 a2004 a2006 -1,2-4,8-16,32 write down the nth number according to the rule

If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". What is A2 If A1 = - 1 / 2, from the second number, each number is equal to "the reciprocal of the difference between 1 and the number before it". A2.a3.a4 a2004 a2006 -1,2-4,8-16,32 write down the nth number according to the rule

The results show that A2 = 2 / 3, A3 = 3, A4 = - 1 / 2
Because A1 = A4, it must be a cycle
It can be seen that the cycle period is 3, that is, every three numbers are the same
2004 / 3 = 668, divisible,
So a2004 = A3 = 3
Then a2006 = A5 = A2 = 2 / 3
A supplementary:
The nth number is (- 1) ^ n × 2 ^ (n-1)

From 1.2.3.4.. 12, take any 7 numbers, among which the difference is equal to six. How many pairs are there at least!

One pair, put two numbers with a difference of 6 in one drawer, there are six drawers, at least one in each drawer, take out six numbers, and one in the drawer no matter how you take it, so the seventh number must have a difference of 6

1/18+1/54+1/108+1/180+1/270

1/18+1/54+1/108+1/180+1/270
=1/18(1+1/3+1/6+1/10+1/15)
=1/18(1+1/3+1/6+1/6)
=1/18(1+1/3+1/3)
=1/18×5/3
=5/54

What is the quotient product of the difference of 760 minus 685 multiplied by 266 divided by 19?

(760-685)×(266÷19)
=75×14
=1050

What is the difference between the product of 48 and 15 minus the quotient of 64 divided by 4? What is the quotient of 740 minus the product of 25 and 8 and then divided by 60?

704
nine

What's the quotient of 6 minus the product of 3.6 and 2 / 3 and dividing by 18 / 5
Primary school new curriculum standard learning and practice optimization test sixth grade mathematics (1) Volume 13

1

What is the quotient of the product of 33 / 5 and 2 / 3 minus 13 / 5 and then divided by 18 / 5?
How to make a formula

Answer 1 / 2
(（33/5×2/3）-13/5))÷18/5

What's the sum of three eighths times three fifths plus three twentieth divided by one fourth?

Three eighths times three fifths, plus three twentieth divided by one fourth
Sum = 3 / 8 × 3 / 5 + (3 / 20) / (1 / 4)
=9/40+3/5
=33/40

If you want to divide bracket 5 by 6, the quotient is one digit, what is the maximum number in bracket? If you want to divide bracket 5 by 6, what is the minimum number in bracket

To divide bracket 5 by 6, the quotient is one digit, the maximum number in bracket is 5, and the minimum number in bracket is 6

What is 980-980 divided by (262-234)
Steps to take

980-980 divided by (262-234)
=980-980÷(28)
=980-35
=945